Show merge requests which close current issue

8 files changed, 39 insertions, 2 deletions

diff --git a/app/assets/stylesheets/pages/issues.scss b/app/assets/stylesheets/pages/issues.scss
index 4bf58cb4a59..41c069f0ad3 100644
--- a/app/assets/stylesheets/pages/issues.scss
+++ b/app/assets/stylesheets/pages/issues.scss
@@ -132,6 +132,11 @@ form.edit-issue {
   }
 }
 
+.issue-closed-by-widget {
+  padding: 16px 0;
+  margin: 0px;
+}
+
 .issue-form .select2-container {
   width: 250px !important;
 }
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index 97485c101fb..eaf14009242 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -14,6 +14,9 @@ class Projects::IssuesController < Projects::ApplicationController
   # Allow issues bulk update
   before_action :authorize_admin_issues!, only: [:bulk_update]
 
+  # Cross-reference merge requests
+  before_action :closed_by_merge_requests, only: [:show]
+
   respond_to :html
 
   def index
@@ -112,6 +115,10 @@ class Projects::IssuesController < Projects::ApplicationController
     render nothing: true
   end
 
+  def closed_by_merge_requests
+    @closed_by_mr = @issue.closed_by_merge_requests(current_user)
+  end
+
   protected
 
   def issue
diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 98df6984bf7..0d9c5461959 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -259,7 +259,7 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     @commits = @merge_request.commits
 
     @merge_request_diff = @merge_request.merge_request_diff
-    
+
     if @merge_request.locked_long_ago?
       @merge_request.unlock_mr
       @merge_request.close
diff --git a/app/helpers/issues_helper.rb b/app/helpers/issues_helper.rb
index 6ddb37cd0dc..1adbf3a79b1 100644
--- a/app/helpers/issues_helper.rb
+++ b/app/helpers/issues_helper.rb
@@ -83,6 +83,10 @@ module IssuesHelper
     end
   end
 
+  def merge_requests_sentence(merge_requests)
+    merge_requests.map(&:to_reference).to_sentence
+  end
+
   # Required for Gitlab::Markdown::IssueReferenceFilter
   module_function :url_for_issue
 end
diff --git a/app/models/issue.rb b/app/models/issue.rb
index fc7e9abe29e..c24a329847c 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -95,4 +95,14 @@ class Issue < ActiveRecord::Base
   def source_project
     project
   end
+
+  # From all notes on this issue, we'll select the system notes about linked
+  # merge requests. Of those, the MRs closing `self` are returned.
+  def closed_by_merge_requests(current_user)
+    notes.system.flat_map do |note|
+      ext = Gitlab::ReferenceExtractor.new(self.project, current_user)
+      ext.analyze(note.note)
+      ext.merge_requests
+    end.uniq.select { |mr| mr.closes_issue?(self) }
+  end
 end
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index c83b15c7d39..3ae74ceac68 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -294,6 +294,10 @@ class MergeRequest < ActiveRecord::Base
     target_project
   end
 
+  def closes_issue?(issue)
+    closes_issues.include?(issue)
+  end
+
   # Return the set of issues that will be closed if this merge request is accepted.
   def closes_issues(current_user = self.author)
     if target_branch == project.default_branch
diff --git a/app/views/projects/issues/_closed_by_box.html.haml b/app/views/projects/issues/_closed_by_box.html.haml
new file mode 100644
index 00000000000..fe886b6d7d7
--- /dev/null
+++ b/app/views/projects/issues/_closed_by_box.html.haml
@@ -0,0 +1,6 @@
+.issue-closed-by-widget 
+  %i.fa.fa-check
+  - if @closed_by_mr.count == 1
+    This issue will be closed when #{gfm(@closed_by_mr.first.to_reference)} is accepted.
+  -else 
+    This issue will be closed when any of merge requests #{gfm(merge_requests_sentence(@closed_by_mr.sort))} is accepted.
diff --git a/app/views/projects/issues/show.html.haml b/app/views/projects/issues/show.html.haml
index 5cb814c9ea8..309f276882d 100644
--- a/app/views/projects/issues/show.html.haml
+++ b/app/views/projects/issues/show.html.haml
@@ -46,6 +46,7 @@
                 = markdown(@issue.description)
             %textarea.hidden.js-task-list-field
               = @issue.description
-
+  - if @closed_by_mr.present?
+    = render 'projects/issues/closed_by_box'
   .issue-discussion
     = render 'projects/issues/discussion'